Make sure you have permissions for the environment! Don't want any copyright infringement issues...
On a separate topic, I admire your ability to create decent scenery with supports, but you should really look into using 3ds. They're MUCH more realistic, and are so much more useful for different things.
^^They only kill FPS if a) your computer can't handle them or b) they're made poorly. If you optimize them, they can look like a real park, without killing FPS. Plus, it's not all wood when you use 3ds.